This invention pertains to a patient monitoring system and switch for providing alarm signals to indicate that the patient has left an object which he has been occupying such as a bed, chair, or like object.
There are various types of patient monitoring systems and switches which have heretofore been proposed. An ensuing section of this application entitled "Prior Art Statement" discusses selected types which were developed as a result of a novelty search conducted in connection with the present invention. A principal purpose of certain patient monitoring systems is to provide an alarm signal to attending personnel that the patient is in danger of falling from or has just left the object which he has been occupying. The systems are frequently used where the patient is in such a physical state that the attending personnel should be immediately summoned if the patient is in such imminent danger of falling from or has just left the object.
The present invention provides an improved patient monitoring system and switch. One feature of the system is that both audible and visible alarm signals are given, with the audible alarm being immediately given and with the visible alarm being given shortly thereafter. In this manner the audible alarm may be momentarily given without the visible alarm being given. However, should the audible alarm be given longer than just momentarily, then the visible alarm is given. Once the visible alarm has been given it continues until reset by attending personnel, even though the audible alarm may be terminated earlier by the return of the patient to the proper position. Uniquely constructed electronic solid state circuitry implements this feature. The circuitry includes a three position control switch for establishing off, on, and test modes of operation. The system is powered by a D.C. battery, and the circuitry includes a low voltage monitor which causes the audible alarm only to be given when the battery voltage drops below a critical level indicative of the need to replace the battery. The circuitry is designed, however, to remain operative over a limited range of battery voltage below the critical level thereby affording a certain time to replace the battery before the visible system fails for lack of power. Another feature of the invention relates to the patient monitoring switch itself. The switch has a generally planar configuration for placement on a bed, preferably between the mattress and the spring. The switching element itself is a tape switch which is arranged in a T-shape configuration whose overall dimensions are generally coextensive with the overall dimensions of the planar configuration. The switch is foldable in half from its planar configuration so that it may be placed on a smaller object of patient occupancy, such as the seat of a chair.
The foregoing features, along with additional features, advantages, and benefits of the invention, become more apparent in the ensuing description and accompanying drawings which disclose the invention in detail. A preferred embodiment is disclosed in accordance with the best mode presently contemplated in carrying out the invention. The subject matter in which an exclusive property is claimed is set forth in each of the numbered claims at the conclusion of the description, and such subject matter is considered patentable over the prior art of which applicant is aware, as set forth in the following Prior Art Statement.